Refactor Spaces concepts - AWS Migration Hub Refactor Spaces

Refactor Spaces concepts

This section describes the key components that you can create and manage when using AWS Migration Hub Refactor Spaces.


The Refactor Spaces environment contains Refactor Spaces applications and services. The environment provides the infrastructure, multi-account networking, and routing that you need to modernize incrementally, along with a unified view of networking, applications, and services across multiple AWS accounts. Refactor Spaces also includes a multi-account network fabric consisting of bridged virtual private clouds (VPCs). This way, resources within the fabric can interact through private IP addresses.

The environment owner is the account that the Refactor Spaces environment is created in. The environment owner has cross-account visibility into applications, services, and routes created in the environment, regardless of the account that creates the resource.


A Refactor Spaces application contains services and routes and provides a single external endpoint to expose the application to external callers. The application provides a Strangler Fig proxy for incremental application refactoring. For information about Strangler Fig, see Strangler Fig Application.

The Refactor Spaces application models the Strangler Fig pattern and orchestrates Amazon API Gateway, API Gateway VPC links, Network Load Balancer, and resource-based AWS Identity and Access Management (IAM) policies so that you can transparently add new services to the application’s HTTP endpoint. It also incrementally routes traffic away from your existing application to the new services. This keeps the underlying architecture changes transparent to the application consumer.


Refactor Spaces services provide your application’s business capabilities and are reachable through unique endpoints. Service endpoints are one of two types: an HTTP/HTTPS URL, or an AWS Lambda function.

After the services are created, Refactor Spaces handles automatic Domain Name System (DNS) resolution for these services. This periodic DNS resolution ensures that the route configuration remains up-to-date and it enables users to create services with DNS names in the URL. Refactor Spaces automatically updates the DNS name when the DNS time-to-live (TTL) expires (or every 60 seconds for TTLs less than 60 seconds).


A Refactor Spaces route is a proxy matching rule that forwards a request to a service. Each request is run against the set of routes configured in the application. If a rule matches, the request is sent to the target service configured for that rule. Applications have a default route that forwards requests to a default service if they don’t match any of the rules.

Routes can be toggled between either an active or inactive state as you prepare and release the routes for traffic. Routes are configured on the application's Amazon API Gateway proxy.

You can create routes with path parameters. Refactor Spaces forwards the path parameters that you define to the target service.